Sightings of "Newborn" Galaxies Reveal a Fecund Universe

NASA/JPL-CALTECH
The first data returned by NASA's Galaxy Evolution Explorer spacecraft (GALEX) suggests that our Universe is still quite fertile. Observations of newborn galaxies indicate that the universe is still alive with youth and not suffering from as big a decline in its galactic birthrate as previously believed.

Launched in April 2003, the spacecraft uses a telescope 50 centimeters in diameter to scan the skies for ultraviolet sources. The newly discovered galaxies are 10 times as bright in the ultraviolet range as the Milky Way. Such brightness is a sign of violent star formation and exploding supernovae, which is in turn an indication of youthful galaxies. "Now we can study the ancestors to galaxies much like our Milky Way in much more detail than ever before," explains project leader Tim Heckman of Johns Hopkins University. "It's like finding a living fossil in your own backyard. We thought this type of galaxy had gone extinct, but in fact newborn galaxies are alive and well in the universe."

Previous discoveries of young galaxies were located some 11 billion light-years away. GALEX's field of view, which spans a stretch of sky nearly three times the moon's diameter, surveyed thousands of galaxies before identifying nearly three dozen newborns. The new finds, just two to four billion light-years from Earth, give astronomers a close-up view of baby galaxies. A report detailing this and other early GALEX results will be published in an upcoming issue of Astrophysical Journal Letters.